Update all instances of MinimumPreferenceOccurances to directly use T…

…ransitionCriterion (facebookresearch#327)

Summary:
X-link: facebook/Ax#2135


This diff updates MinimumPreferenceOccurances to directly inherit from its source in TransitionCriterion file

In following diffs we will:
- Completely remove the completion criterion file
- update all four completion criterion defined in aepsych code here: https://www.internalfb.com/code/fbsource/[409e3dfb01ec5c613d34e58c491d63e8051d10d9]/fbcode/frl/ae/aepsych/tests/generators/test_completion_criteria.py?lines=12-15
- revisit storage
- remove all todos in gennode, genstrat, and transitioncriterion classes related to maintaining this deprecated code
- update AEPsych GSs as needed
- determine if run indefinetly can be replaced by simply having gen_unlimited_trials = true

Reviewed By: lena-kashtelyan

Differential Revision: D52852317

aepsych/generators/completion_criterion/min_total_outcome_occurrences.py

@@ -9,7 +9,7 @@
 
 from aepsych.config import Config, ConfigurableMixin
 
-from ax.modelbridge.completion_criterion import MinimumPreferenceOccurances
+from ax.modelbridge.transition_criterion import MinimumPreferenceOccurances
 
 
 class MinTotalOutcomeOccurrences(MinimumPreferenceOccurances, ConfigurableMixin):